12 31... Replacing alternator belt pulley

Special tools required: 

• 12 7 121
• 12 7 122

PROCEDURE WITH SPECIAL TOOL 12 7 121 

Illustrations show N42:

If fitted, remove cover cap from belt pulley.

Depending on alternator type, slacken screw with:

• Torx socket wrench
• Slacken multi-tooth socket wrench (special tool 12 7 122  ).

Grip freewheel with special tool 12 7 121  .

Installation: 

Tightening torque 12 31 8AZ .

Remove alternator drive belt.

Release screw and if necessary remove freewheel.

Fig 1: Identifying Special Tool (12 7 121) And (12 7 122)

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Identifying Special Tool (12 7 123)

PROCEDURE WITH SPECIAL TOOL 12 7 123 

Depending on the alternator version, hold down alternator axis with: Torx key and Hold inner multi-wrench tool (special tool 12 7 122).

Release freewheel with special tool 12 7 123 and a ring spanner and remove. Installation note:  Tightening torque 12 31 8AZ .